Artificial Muscles Use Carbon Nanotube Sheets

Light as air, stronger than steel and more flexible than rubber. Sound like something from the next installment of the Iron Man series? [Tony Stark] would certainly take notice of this fascinating technology. Fortunately for us, it does not come from the studios of Hollywood, but instead the halls of the NanoTech Institute at the University of Texas.

Professor [Ray Baughman] and his team of scientists at the NanoTech Institute have developed a type of artificial muscle through a process of making aerogel sheets by growing carbon nanotubes in a forest like structure. Think of a vertical bamboo forest, with each bamboo stem representing a single carbon nanotube. Now imagine that the individual bamboo stems were connected together by much smaller horizontal threads. So that if you dislodge the bamboo and began to pull, the threads would pull the others, and you would get this sheet-like structure.

These aerogel sheets of carbon nantubes have some truly science fiction like properties. They can operate from 1,600 degrees centigrade to near absolute zero. If you inject a charge, each nanotube will be repulsed from one another, expanding some 220% of the sheet’s original size. Your muscles do this at roughly 20 – 40%. Stick around after the break for a video demonstration of these carbon nanotube aerogel sheets being made and demonstrated.

Carbon Nanotubes don’t behave like asbestos. Asbestos is an Alkaline Earth metal bonded to a silicate complex. When it breaks down it releases ions with a +2 charge, and that is what damages DNA and other materials and can cause cancer. Carbon nanotubes have a much higher dissociation energy and thus will affect the body much less. Also, they are not making an aerosol of nanotubes and spraying it around, they are making flexible materials. Asbestos is not scary at all, you just need to know how to deal with it, some Hydrofluoric acid will break it down into harmless salt water. Not to mention asbestos is naturally occurring, not man-made.

“When it breaks down it releases ions with a +2 charge, and that is what damages DNA and other materials and can cause cancer.”

The problem is it doesn’t break down in the body.

“Carbon nanotubes have a much higher dissociation energy and thus will affect the body much less.”

This assumes the body can metabolize it. Can the body metabolize or even slowly break down a diamond? Buckyball? Probably not.

“Also, they are not making an aerosol of nanotubes and spraying it around, they are making flexible materials.”

True, but it’s lighter than air and some of it will invariably become airborne. Or otherwise integrated into the body.

“Asbestos is not scary at all, you just need to know how to deal with it, some Hydrofluoric acid will break it down into harmless salt water.”

Sure, and dissociate all of your calcium, damage your lungs and eyes and stop your heart. Sodium hydroxide will dissolve it too but that’s going to saponify you in the process. Also, how exactly do you get Mg3Si2O5(OH)4 + HF —> NaCl is beyond me. HF + asbestos yields fluorosilicic acid.

“Not to mention asbestos is naturally occurring, not man-made.”

Well shit, mercury and cesium and radon are naturally occurring too! Doesn’t make them safe.

I am not saying CNTs are certainly bad but they could be and we should endeavor to understand them more from a safety perspective.

A- You’re really very worried about inhaling things made of (SWCNT/DWCNT) string, because of all the fragging you do
B- You feel like legislation would fix you up
C- Nobody thinks NO (nitrous…yes, the mucous membrane thing) is the thing to bear?
D- So close to implementing the definition of an ampere (2×10^7N across a meter) without the vacuum thing, they had to change the definition to keep it abtruse.
E- Bad experience with clothes made of very fine threads
You are ready to run for office!

No, there’s a matter of degrees. As a control in one study on the effect of carbon nanotubes on lungs, researchers exposed the control group (of mice) to ultrafine carbon black, which turned out to have much less impact on the lungs. Carbon naotubes have unique properties and it’s not at all surprising that they have unique effects when introduced into living tissues. That doesn’t mean they should be banned, but it does mean that safety needs to be kept in mind. Are you suggesting otherwise, that we completely ignore safety and just pretend it’s all paranoia?

My understanding was that asbestos has tiny hooks which attach themselves to the lungs and block normal oxygen transfer thus causing asbestosis which eventually blocks the lungs . I have been using asbestos my whole younger life to 30 with a mask and am now 67 with no lung problems at all. I smoked heavily 50 a day up to 50 yrs and often drank a bottle of rum a day again up to 50 yrs then stopped it all . There do not appear to be any after effects at all .
I think the WOWSERS are still alive and getting worse . This is an example of just plain stupid overreaction here.

People used asbestos for 50 years an we’re not all dead. It would be foolish to give up amazing capacitors and batteries, solar cells, new display technologies, super strong materials, and now these artificial muscles over a concern that some people will fail to treat the material with the proper precautions.

Yes, we all know that power is Voltage * Current and so if the current is low enough than theoretically we are looking rosy on the power efficiency front. However, on a practical level needing to generate and control 5K Volts at any current is lot less convenient than needing only 5 or even 50 volts.

A taser can generate 50K volts in a handheld device and deliver it over very thin wires to a target. As long as it doesn’t require a lot of current, I don’t see using this to build robots being a major challenge.

Most of their measurements about strength and force were on a per-weight basis. Since the aerogels weigh so little, it would probably be hard to measure any work they can do.

I think it would take a lot of these strands to do anything noteworthy. Also, once you do work with a muscle like this, you would have to put that much energy into the muscle with additional charge as the muscle expands. If you’re clever with your driving circuitry, you might be able to get the energy back when it relaxes.

If I understood the video correctly, the muscles contract by expanding laterally, so if you put a bunch of these side-by-side to make it stronger, you might get some vastly diminishing returns…

Not yet.
I do wonder if we can hang something like this down a bit, to have a sort of half-way space elevator though. It wouldn’t be geostationary, so youd have to hock onto it at speed.
Still, thats a minor problem compared to a “true” space elevator – and you’d still have significant energy vs rockets to orbit.
Dunno if even that much is possible with this material though.

I do love that last statement linking this technology to solar cells, yet not connecting the two technologies logically at all. It can make solar cells more efficient? That sure is relevant/makes sense after the entire video talks about the mechanical properties of the material.

If you could fashion the sheets into muscle stands you could hypothetically build an artificial heart strand by strand electrically isolate each chamber L+R atrium, L+R ventricle settle on a valve design, controller and power supply then test it..